1. Field of the Invention
The present invention relates to a pair of tool-free self-assembly glasses. In particular, it relates to an assembly of glasses frame and legs with a single-piece appearance, which are easily manufactured, readily assembled, and still possesses substantial stability in its simple structure.
2. Background Art
Conventional glasses include a frame and two legs in addition to the lens. The engagement of a leg to the side of the frame is realized in many different ways. Problems associated with a variety of prior arts can be summarized as two main kinds. The first kind of problems occurs when stability of the frame-leg connection is at its optimal while inconvenience in repairing or replacing a broken piece connecting the frame and a leg is accordingly increased. The second kind of problems is the opposite of the first kind, which occurs when convenience in replacing a broken piece fixing the frame and a leg is at its optimal, while stability of the frame-leg attachment is significantly reduced. Another problem associated with the above two main problems resides in the outer appearance of the glasses, of which the frame-legs connecting piece is expected not to be seen after complete assembly. Some prior arts with the above-stated problems are discussed below in more details.
For most conventional glasses, a frame-leg connecting piece on either side of the frame is used for engaging a leg to the frame. Such a frame-leg connecting piece is often formed by two planes with an angle greater than 90-degree such that one end of the frame-leg connecting piece is welded with one end of a frame, while the other end of the frame-leg piece is screwed in with the glasses leg. As a result, glasses legs can be adjusted to open or fold by moving the leg round the end of its connecting piece into which the leg is screwed.
Since one end of the frame-leg piece is screwed into a glasses leg, screws or bolts, and a screw driver which fits in with the screws or bolts are necessary tools for assembly. Furthermore, welding or soldering techniques applied in fixing the frame-leg connecting piece to the frame is not cost effective in manufacture; as a permanent fixing method, welding or soldering also lacks flexibility in replacement of a broken connecting piece.
To overcome the above-mentioned disadvantages, some conventional glasses are designed for connecting pieces to be readily assembled with the frame. Such an improved design is embodied by forming connection grooves on either side of the frame, and in the mean time, having raised bulbs protruding out on the very upper end of the leg for fixing into the corresponding connection grooves. However, both connection grooves and raised bulbs used for connection purpose are exposed outside after complete assembly, degrading the overall appearance of the glasses.
Some conventional glasses are made with two legs of which each of the upper end is formed with a protruding member of a plurality of teeth for attaching to the embedded groove on either side of the frame. The securing of the legs inside the embedded groove of the frame therefore relies on the protruding teeth only, which covers limited frame-leg contact surface; legs may easily be separated from the frame.
For some other conventional glasses, clasp hooks are used as an alternative frame-leg connecting member. The problem is that it is not an easy job to disassemble a clasp hook connecting member when it comes to replacing a broken hook.
It is therefore the purpose of this invention to provide a cost-effective compact glasses frame and legs assembly, which is easy to be manufactured, tool-free readily assembled, and yet maintains substantial stability, and a single-piece elegant look with the frame-leg connecting piece hidden within its structure.